1. The electrostatic force of attraction between two small spheres that are 1.0 meter apart is F. If the distance between the spheres is decreased to 0.5 meter, the electrostatic force will be

a) F/2
b) 2f
c) F/4
d) 4F

I know when the distance is decreased the Fe would decrease as well.

2. Two identical spheres, A and B, carry charges of +6 microcoulombs and -2 microcoulombs. If these spheres touch, what will be the resulting charge on sphere A?

3 answers

1. What yu "know" is wrong. The attraction force increases when they get closer together. Have you heard of "inverse square law" behavior?

It applies here. Use it to figure out the answer.

2. The charges can move. The charges redistribute so that the total charge remains the same (4 uC) but each sphere has the same charge (because they are identical). That would have to be half of 4 uC.
1. The electrostatic force of attraction between two small spheres that are 1.0 meter apart is F. If the distance between the spheres is decreased to 0.5 meter, the electrostatic force will be

a) F/2
b) 2f
c) F/4
d) 4F
----------------------
F = k/r^2
F = k/1^2
k = 1F for our purposes

Fnew = F/(.5)^2
Fnew = F/.25 = 4F
k, thanks a lot. Have a good day :)